Vapor lock eliminator



Feb. 6, 1940. B. E. SIBLEY' VAPOR LOCK ELIMINATOR Filed Sept. 14, 1935 Patented Feb. 6, 1940 UNITED STATES PATENT OFFICE VAPOR LOCK ELIMINATOR Barrett E. Sibley, Continental Oil Ponca City, Okla; assignor to Company,

Ponca City, Okla., a

3 Claims.

My invention relates to a vapor lock eliminator for use in connection with internal combustion engines.

Modern motor fuels always contain light ends which are readily vaporized and assist in case of starting and proper acceleration. These fuels are designed for average use. If an internal combustion engine runs excessively hot, as is sometimes the case in warm climates and during hot weather or traversing high altitudes, the light ends contained in the fuel will vaporize or gasify and produce what is commonly termed vapor lock. The vapor lock interrupts the supply of gasoline by breaking suction either in the fuel pump or in the vacuum tank. The difficulty with vapor lock is frequently encountered in mountainous areas and during the hot summer days.

One object of my invention is to provide a means for eliminating vapor locking difficulties, independent of the quantity of light ends in the motor fuel.

Another object of my invention is to provide a means for eliminating vapor lock whereby a fuel which gives easy starting and acceleration may be used under a variety of conditions of temperature and pressure without producing a vapor lock.

Another object of my invention is to provide a means for enabling a reduction in fuel consumption and the elimination of knocking by employing the Volatile portions of a motor fuel which are high in antiknock qualities.

Other and further objects of my invention will appear from the following description.

In the accompanying drawing which forms part of the instant specification and is to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

Figure l is a schematic View, partly in section, of an internal combustion engine fitted with one embodiment of my invention in which a fuel pump is used.

Figure 2 is an enlarged sectional elevation of a chamber used in my invention.

Figure 3 is a sectional View taken along the line 33 of Figure 2.

Figure 4 is a view similar to Figure 1, showing another embodiment of my invention in connection with an internal combustion engine in which a vacuum tank is used for supplying fuel.

In general, my invention contemplates the provision of a standpipe inthe line supplying fuel to the carburetor or vaporizing device of the internal combustion engine, to which standpipe is fitted a separating chamber adapted to release gasified light ends. The light ends which are separated in the separating chamber are supplied to the explosive mixture being fed to the 5 intake manifold of the internal combustion engine.

More particularly referring now to the drawings, fuel from fuel tank I is supplied through conduit 2, by pump 3 to a carburetor 4 in which 10 the fuel is vaporized by means of air being supplied through the air inlet 5. The vaporized mixture passes through duct 6 to the intake manifold l-of the internal combustion engine 8. A T 9 is provided in the conduit 2, between the 16 fuel tank I and the pump 3. A standpipe Ill communicates with the T through a check valve II. The standpipe Ill is connected by flexible conector l2 to a chamber l3 which is provided with 'a baflle plate l4 and partially filled with a 20 material having extended surface. such as steel wool I5, glassbeads, or the like. The upper end of chamber l3 communicates through pipe l6, which is provided with a flexible joint I! with a trap l8, the upper arm of [which extends into the air inlet pipe 5.

Flexible connections I 2 and H are employed to permit movement of the engine with respect to the chamber l3 which is usually mounted on a partition I9 or any other convenient place. The check valve H is very lightly loaded and with a minimum spring tension, employing only suflicient pressure to seat the valve. The purpose of the check valve is to prevent breaking suction of the fuel pump. The object of using low pressure to seat the valve is to permit the escape of gas bubbles and fuel through the standpipe IIJ into the chamber l3. It is these gas bubbles which cause a vapor look. In practice, the escape of gas bubbles and the vapor pressure of the fuel in fuel tank I tends to carry liquid fuel into the chamber l3 The baiiiing and the steel wool or other material having extended surface, positioned in chamber l3 serves to enable gas to be freed from the liquid and rise into the upper portion of the chamber from which it is conducted by pipe Hi to the trap l8. The function of the trap is to accumulate such gaseous material as might condense, as would occur when the motor cools down. This material is highly volatile and the liquid which collects in the trap 18 will be drawn in by the air when the motor is started, thus promoting the easy starting of the motor. The upper end of the trap which extends into the air passage is so shaped that passage of the air will produce an area of reduced pressure at the mouth of the pipe, thus permitting the flow of the air to pull the gas or gaseous vapor out of the trap l8 into the carburetor.

Where a vacuum tank is employed, no check valve is used. Figure 4 shows the arrangement with an internal combustion engine using a vacuum tank 20. The chamber I3 is placed at a higher level than the vacuum tank and acts in the same manner described in connection with Figure 1.

The size of chamber [3 is not critical, provided it is of sufficient area to permit a separation of gas from such fuel as is passed into the chamber.

During the testing of my device during extremely hot weather last summer, I employed a fuel which was unusually volatile and had a large quantitypf propane which it is well known is easily volatilized and tends to produce vapor look. I tested the device in use in mountainous areas where a comparatively rapid change in altitude was experienced. I found that, with my device, an automobile was free of vapor locking difficulties in the hottest of weather at high altitudes employing volatile fuel. When my device was removed, vapor lock was immediately obtained and the fuel supply interrupted.

In addition to eliminating vapor look, I observed a slight improvement in fuel economy and a more flexible motor operation. The light gases which cause vapor locking difliculties, which would otherwise escape just after their arrival in the carburetor bowl, are taken out of the fuel before it reaches the carburetor and delivered to the engine through the air intake. These volatile gases generally have a higher antiknock value than the less volatile portions of the fuel. It will be seen, therefore, that employing them to do useful work slightly increases the fuel economy and tends to reduce knocking. The result is that besides eliminating vapor look there is a somewhat more economical and smoother operation of the motor. Ease of starting and acceleration assistance given by the light ends are retained.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details Within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1. In combination with an internal combustion engine, a carburetor, a fuel supply for fuel having a high vapor pressure, a conduit for conducting fuel from said supply to said carburetor, a fuel pump in said conduit, a chamber positioned above said conduit, a pipe providing communication between said chamber and said conduit at a point therein between said fuel supply and said pump, said fuel supply being positioned to maintain some fuel in said pipe and a vent for said chamber.

2. The combination as in claim 1 wherein said pipe is provided with a check valve.

3. In combination with an internal combustion engine, a carburetor having an air intake, a high vapor pressure fuel supply, a conduit for conducting fuel from said supply to said carburetor, a chamber positioned above said conduit, material having an extended surface positioned in said chamber, a pipe providing communication between said conduit and the lower part of said chamber, and a pipe providing communication between the upper part of said chamber and the air intake of said carburetor, said fuel supply being such as to maintain some fuel in said pipe.

BARRETT E. SIBLEY. 

